Separation of liquid mixtures by membranes.
type: CreativeWork
description: The study focused on the interface, morphology and transport involved in pervaporation and reverse osmosis separation of liquid mixtures. The first part of this study concerns pervaporation separation of liquid mixtures. A fluorine-containing surface modifying macromolecule (SMM) was added into a polyethersulfone (PES) membrane casting solution. Because of its lower surface energy, SMM is expected to move up to the top surface of the membrane. The resulting membrane is to have a layer of SMM at the top surface and a PES rich bulk substrate underneath. Asymmetric PES/SMM membranes were fabricated by the phase inversion method under various conditions and tested in pervaporation separation of chloroform/water mixtures. The principal findings are: (i)The contact angles of water on the surface of PES/SMM membranes were significantly larger than those of PES membranes. (ii) The XPS results indicate a much higher fluorine concentration at the membrane surface than in the bulk and upwards orientation of SMM's fluorine tail at the membrane surface. It is concluded that SMM migrates to and accumulates at the membrane-air interface. The membrane surface can be covered by a layer of SMM. (iii) A PES/SMM membrane has a superior performance to a PES membrane for pervaporation separation of chloroform/water mixtures, since the former has a much higher water selectivity than the latter. (iv) A PES/SMM membrane has a higher permeation rate of n-heptane and a lower permeation rate of ethyl alcohol than a PES membrane in pervaporation separation of ethyl alcohol/n-heptane mixtures. The second part of this study concerns reverse osmosis of liquid mixtures. A new method to determine the preferential sorption in binary mixtures based on liquid chromatography is presented. Liquid chromatography and liquid sorption experiments were performed for cellulose acetate butyrate (CAB)/ethyl alcohol/n-heptane system. An interaction force constant characterizing the interaction between the feed sp…
abstract: The study focused on the interface, morphology and transport involved in pervaporation and reverse osmosis separation of liquid mixtures. The first part of this study concerns pervaporation separation of liquid mixtures. A fluorine-containing surface modifying macromolecule (SMM) was added into a polyethersulfone (PES) membrane casting solution. Because of its lower surface energy, SMM is expected to move up to the top surface of the membrane. The resulting membrane is to have a layer of SMM at the top surface and a PES rich bulk substrate underneath. Asymmetric PES/SMM membranes were fabricated by the phase inversion method under various conditions and tested in pervaporation separation of chloroform/water mixtures. The principal findings are: (i)The contact angles of water on the surface of PES/SMM membranes were significantly larger than those of PES membranes. (ii) The XPS results indicate a much higher fluorine concentration at the membrane surface than in the bulk and upwards orientation of SMM's fluorine tail at the membrane surface. It is concluded that SMM migrates to and accumulates at the membrane-air interface. The membrane surface can be covered by a layer of SMM. (iii) A PES/SMM membrane has a superior performance to a PES membrane for pervaporation separation of chloroform/water mixtures, since the former has a much higher water selectivity than the latter. (iv) A PES/SMM membrane has a higher permeation rate of n-heptane and a lower permeation rate of ethyl alcohol than a PES membrane in pervaporation separation of ethyl alcohol/n-heptane mixtures. The second part of this study concerns reverse osmosis of liquid mixtures. A new method to determine the preferential sorption in binary mixtures based on liquid chromatography is presented. Liquid chromatography and liquid sorption experiments were performed for cellulose acetate butyrate (CAB)/ethyl alcohol/n-heptane system. An interaction force constant characterizing the interaction between the feed sp…
author: Fang, Yi.
keywords: Engineering, Chemical.
identifier: Source: Dissertation Abstracts International, Volume: 58-06, Section: B, page: 3176.
date published: 2009-03-25T20:06:49Z
date modified: 2026-07-24T03:39:23Z
provider: University of Ottawa
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Ottawa (Canada)

PropertyValue
property ID: Handle
value: http://hdl.handle.net/10393/10164

PropertyValue
property ID: DOI
value: 10.20381/ruor-8158